In the field of manufacture of a semiconductor device or the like, a shower head for supplying a gas toward a substrate such as a semiconductor wafer in a shower pattern has been conventionally used. To be specific, in a plasma processing apparatus that performs a plasma etching process on a substrate such as a semiconductor wafer, a mounting table for mounting the substrate thereon is installed in a processing chamber, and the shower head is installed so as to face the mounting table. The shower head is provided with a multiple number of gas discharge holes on its surface facing the mounting table, and a gas is supplied toward the substrate through the gas discharge holes in a shower pattern.
In such a plasma processing apparatus, along with a trend toward scaling-up of a semiconductor wafer, it is required to uniformly perform a plasma process on an entire surface of a semiconductor wafer of a large diameter. Therefore, there has been known a technique for confining plasma between a mesh-shaped anode electrode and a cathode electrode which mounts thereon a semiconductor substrate in a processing chamber by covering the cathode electrode with the anode electrode (see, e.g., Patent Document 1).    Patent Document 1: Japanese Patent Laid-open Publication No. 2005-217300
As described above, in the plasma processing apparatus, due to the trend toward scaling-up of a semiconductor wafer, it is difficult to uniformly process an entire surface of a semiconductor wafer having a large diameter. Accordingly, there has been demanded development of a plasma processing apparatus capable of improving processing uniformity in the surface of the semiconductor wafer.